Authorities also confirmed that no animals escaped from the enclosure and the incident is “not suspicious.”

Zoo-goers were evacuated from the park after police and medical personnel were called to attend to a “serious incident” around 11 a.m. local time.

Victoria Northover Holmes, who was at the zoo during the incident told UK’s The Sun that she saw zookeepers “with pieces of meat trying to get whatever’s attention.” And that it was “heartbreaking seeing them trying to help,” she said.

The park shut down for the remainder of the day and will remain closed on Tuesday, officials said.

The zoo handed out statements to visitors calling the mauling a “freak accident,” adding that “an investigation is underway.”

“All our thoughts and sympathies are with our colleagues, friends and families at this dreadful time,” the statement said.

The identity of the zookeeper has not been released.

While big cat attacks in zoos are not common, they have taken place several times over the last decade.

Stacey Konwiser, a tiger expert at the Florida’s Palm Beach Zoo, died after a male Malayan tiger left her with critical injuries while she was tending to the animal in an enclosure last year.

In 2013, a 24-year old intern died of a broken neck after being attacked by a 500-pound lion, also inside an enclosure, at the Project Cat Haven park in Dunlap, California.

And a man was killed at the San Francisco Zoo in 2007, when a tiger escaped its enclosure and attacked several zoo patrons.